42 CLASS REPTILIA. 



upon them a wonderful fecundity, and in many species has 

 even doubled the reproductive organs, apparently with a view 

 to increase their multiplication. 



It is at the period of reproduction that the voices of rep- 

 tiles are chiefly to be heard, which vary very considerably. 

 The crocodiles, but more particularly the caymans of 

 America, are said to howl loudly. The hissing of serpents 

 and the croaking of frogs are well known. A traveller 

 towards the desert shores of the Caspian and the Volga, 

 would imagine that he heard of a sudden, in the evening, a 

 joyous assembly of men and women laughing very heartily. 

 He approaches ; the inextinguishable laughter redoubles 

 among the rocks, and, to his astonishment, he finds that it 

 proceeds from an assembly of enormous black toads cele- 

 brating their nuptial orgies. Certain species of America 

 imitate the sound of a funeral bell tolling during the night, 

 and others the rattling noise of cymbals. 



Though reptiles never sit upon their eggs, it does not 

 appear that the sentiment of maternity is altogether non- 

 existent among these animals. There are serpents (and 

 those are particularly the venomous species,) which retain 

 their eggs in their oviductus longer than other animals of 

 their kind. These eggs disclose within, and the young ones 

 come out alive. These animals produce in smaller number 

 than those reptiles which lay their eggs. It is said that the 

 female crocodile lays its eggs on a bed of rushes and sand, 

 and that she covers them with a second and a third similar 

 bed, with other layers of eggs, to conceal them from the 

 watchful ichneumon. The serpents heap up theirs in some 

 hole exposed to the sun. Small lizards have been observed 

 carefully carrying their eggs in the mouth to warmer places, 

 more favourable for the exclusion of the young. But the 

 young, once disclosed, have nothing more to expect from the 

 mother. She has no milk to offer them — she takes no care 



